Recently, a capsule endoscope having an imaging function and a wireless communication function has appeared. During an observation period of time until the capsule endoscope is naturally discharged from a living body (human body) of a person to be examined after it is swallowed by a person to be examined as a subject for the purpose of observation (examination), the imaging function is sequentially performed with the movement of the capsule endoscope resulting from the peristalsis of the inside of organs (inside of the body cavity) such as stomach and small intestine.
During the observation period with the movement in the organs, image data picked up in the body cavity by the capsule endoscope are sequentially transmitted to an external device disposed outside the subject by means of the wireless communication function of radio communication and are stored in a memory disposed in the external device. By allowing the person to be examined to carry the external device having the wireless communication function and the memory function, the person to be examined can move freely during the observation period until the capsule endoscope is discharged after it is swallowed. After the observation, a doctor or a nurse can display the image of the body cavity on display unit such as a display to diagnose the health of the person to be examined on the basis of the image data stored in the memory of the external device.
An example of such a type of capsule endoscope includes a swallowable type shown in Patent Document 1, which discloses a configuration that a reed switch to be turned on or off by an external magnetic field is provided therein so as to control the driving of the capsule endoscope and the capsule endoscope is accommodated in a package including a permanent magnet for supplying the external magnetic field. That is, the reed switch disposed inside the capsule endoscope maintains its OFF state under an environment with a magnetic field greater than a predetermined intensity and is turned on with the decrease in intensity of the external magnetic field. For this reason, the capsule endoscope is not driven in the state where it is accommodated in the package. When the capsule endoscope is swallowed, the capsule endoscope is taken out of the package and the capsule endoscope is separated from the permanent magnet and thus is not affected by the magnetic force, thereby starting its operation. Due to such a configuration, the capsule endoscope can be suppressed from its operation in the state where it is accommodated in the package and can pick up an image using the imaging function and transmit image signals using the wireless communication function of the capsule endoscope after it is taken out of the package.
Patent Document 1: International Publication No. 01/35813 Pamphlet